I bought an ipv4 few months back and everything was going fine until I put my rda on it and it was till working good but whenever I put my sub ohm tank back on it says "Check Atomizer" I don't know what I did wrong but it's not usable. I know I'm not the only one that has had this problem. So if you have/had an IPV4 and you know how to fix it please let me know, if anyone knows please tell me. Thank you in advance!